1. Field of the Invention
This invention is in the field of extendible hand tools which have interchangeable heads and pivoting shafts and are capable of adjustment in the position of the heads. The tools of this invention may have a handle at one end and a tool head at the other or they may be adapted to have a tool head at each end.
2. Description of the Related Art
The prior art is aware of tools having one or more of the above features.
Thus, U.S. Pat. No. 2,978,938 to Nalley describes a wrench having a handle with a telescoping sleeve for extension, a pivotable attachment between the upper and lower sections of the sleeve, and a pivotable attachment between the wrench head and the wrench handle. When the pivoting mechanisms are used, pivoting of the head and lower part of the handle is possible only along one plane (right or left as viewed in FIG. 2). Therefore, a full range of motion is not possible. While it is taught that the wrench handle is moveable in the sleeve for extension and retraction of the handle, no teaching is given as to how this is performed with the handle being held firmly in the desired position.
U.S. Pat. No. 4,901,608 to Shieh discloses a ratchet wrench with an adjustable angle between the head and the body. The wrench head pivots around a bolt and is held in the desired position by teeth in the extension of the head contacting gear teeth in the handle. In spite of the complexity of the device and need for small parts of complex shapes, the head may be made to pivot up and down as seen in FIG. 1 but cannot be made to pivot from side to side. Thus, the Shieh device has limited utility when used in hard-to-reach areas.
U.S. Pat. No. 5,109,737 to Raber discloses a hand tool, generically, and a ratchet wrench, particularly. The handle, containing a detent, fits into a sleeve provided with a plurality of spaced holes, thus allowing for easy extension and retraction of the handle. Extension and retraction may be achieved only when the detent is in line with a hole in the sleeve and thus the handle cannot be extended to every length which may be desired by the user.
U.S. Pat. No. 5,230,263 to Kwaka discloses a wrench which has a handle, a box wrench head fixed to one end of the handle, and a socket wrench head (with or without a ratchet mechanism) pivotally attached to the other end. The pivot mechanism is made up of a pin penetrating a lug protruding from the handle. The movement of the wrench head is frictionally restrained by the interaction of the several component members. Thus, this pivoting mechanism provides for only an up-and-down motion and does not provide for a side-to-side range of motion.
U.S. Pat. No. 5,280,740 to Ernst discloses a hand tool having a pivotal head attached to the shaft by a pin through holes in the head and a clevis in the shaft. The tool is rotatable about its axis. While the head may be made to pivot up and down, no provision is made to provide for a side-to-side pivot. Also, only a single pivoting point is present so that nuts or bolts which are hard to access may be unreachable with this tool.
U.S. Pat. No. 5,305,668 to Davis discloses a wrench with a plurality of pivotable links to enable access to areas which are hard to reach. This tool provides great side-to-side flexibility and is useful for those situations where a plurality of turns do not have to be made to access the nut or bolt. This tool does not provide for vertical flexibility, and thus finds little use in those circumstances where both vertical and horizontal bends must be made to reach hard-to-access nuts and bolts.
U.S. Pat. No. 5,331,869 to Webb discloses a wrench with interchangeable heads and a provision for pivoting the head up or down. No provision for side-to-side pivoting is made. Thus, while this tool finds limited improvement over non-pivoting wrenches, it leaves unmet the need to provide a fully flexible tool which can reach hard-to-access nuts and bolts.
U.S. Pat. No. 5,471,899 to Twomblow discloses an extendible wrench which provides a pivotable head. The head can pivot up or down, but lacks the ability to pivot from side to side. Thus, access to hard-to-reach nuts and bolts is limited.
U.S. Pat. No. 5,836,223 to Lin discloses a head having interchangeable tool pieces and a shaft which may be extended. No provision is made for pivoting the head of this tool. Thus, access to hard-to-reach areas is not provided for.